[LTP] [PATCH v3] syscalls/mmap14: Rewrite test using new LTP API

[LTP] [PATCH v3] syscalls/mmap14: Rewrite test using new LTP API

[Avinesh Kumar]

Signed-off-by: Avinesh Kumar <akumar@suse.de>
---
 testcases/kernel/syscalls/mmap/mmap14.c | 135 ++++++++----------------
 1 file changed, 45 insertions(+), 90 deletions(-)

diff --git a/testcases/kernel/syscalls/mmap/mmap14.c b/testcases/kernel/syscalls/mmap/mmap14.c
index 31632601b..33c6d1ef0 100644
--- a/testcases/kernel/syscalls/mmap/mmap14.c
+++ b/testcases/kernel/syscalls/mmap/mmap14.c
@@ -1,124 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (c) 2013 FNST, DAN LI <li.dan@cn.fujitsu.com>
- *
- * This program is free software;  you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY;  without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
- * the GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program;  if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ * Copyright (c) 2024 SUSE LLC Avinesh Kumar <avinesh.kumar@suse.com>
  */
 
-/*
- * Test Description:
- *  Verify MAP_LOCKED works fine.
- *  "Lock the pages of the mapped region into memory in the manner of mlock(2)."
+/*\
+ * [Description]
  *
- * Expected Result:
- *  mmap() should succeed returning the address of the mapped region,
- *  and this region should be locked into memory.
+ * Verify that, mmap() call with MAP_LOCKED flag successfully locks
+ * the mapped pages into memory.
  */
-#include <stdio.h>
-#include <sys/mman.h>
 
-#include "test.h"
+#include <stdio.h>
+#include "tst_test.h"
 
-#define TEMPFILE        "mmapfile"
-#define MMAPSIZE        (1UL<<20)
+#define MMAPSIZE        (1UL<<22)
 #define LINELEN         256
 
-char *TCID = "mmap14";
-int TST_TOTAL = 1;
-
 static char *addr;
-
 static void getvmlck(unsigned int *lock_sz);
-static void setup(void);
-static void cleanup(void);
+static struct rlimit rlim;
+static unsigned int sz_before;
 
-int main(int argc, char *argv[])
+static void setup(void)
 {
-	int lc;
-	unsigned int sz_before;
-	unsigned int sz_after;
-	unsigned int sz_ch;
-
-	tst_parse_opts(argc, argv, NULL, NULL);
-
-	setup();
-
-	for (lc = 0; TEST_LOOPING(lc); lc++) {
-
-		tst_count = 0;
+	SAFE_GETRLIMIT(RLIMIT_MEMLOCK, &rlim);
 
-		getvmlck(&sz_before);
+	getvmlck(&sz_before);
 
-		addr = mmap(NULL, MMAPSIZE, PROT_READ | PROT_WRITE,
-			    MAP_PRIVATE | MAP_LOCKED | MAP_ANONYMOUS,
-			    -1, 0);
-
-		if (addr == MAP_FAILED) {
-			tst_resm(TFAIL | TERRNO, "mmap of %s failed", TEMPFILE);
-			continue;
-		}
-
-		getvmlck(&sz_after);
-
-		sz_ch = sz_after - sz_before;
-		if (sz_ch == MMAPSIZE / 1024) {
-			tst_resm(TPASS, "Functionality of mmap() "
-					"successful");
-		} else {
-			tst_resm(TFAIL, "Expected %luK locked, "
-					"get %uK locked",
-					MMAPSIZE / 1024, sz_ch);
-		}
-
-		if (munmap(addr, MMAPSIZE) != 0)
-			tst_brkm(TFAIL | TERRNO, NULL, "munmap failed");
-	}
-
-	cleanup();
-	tst_exit();
+	if (((sz_before * 1024) + MMAPSIZE) > rlim.rlim_cur)
+		tst_brk(TCONF, "Trying to exceed RLIMIT_MEMLOCK limit");
 }
 
 void getvmlck(unsigned int *lock_sz)
 {
-	int ret;
 	char line[LINELEN];
-	FILE *fstatus = NULL;
+	FILE *fp = NULL;
 
-	fstatus = fopen("/proc/self/status", "r");
-	if (fstatus == NULL)
-		tst_brkm(TFAIL | TERRNO, NULL, "Open dev status failed");
+	fp = fopen("/proc/self/status", "r");
+	if (fp == NULL)
+		tst_brk(TFAIL | TERRNO, "could not open status file");
 
-	while (fgets(line, LINELEN, fstatus) != NULL)
+	while (fgets(line, LINELEN, fp) != NULL) {
 		if (strstr(line, "VmLck") != NULL)
 			break;
+	}
 
-	ret = sscanf(line, "%*[^0-9]%d%*[^0-9]", lock_sz);
-	if (ret != 1)
-		tst_brkm(TFAIL | TERRNO, NULL, "Get lock size failed");
+	if (sscanf(line, "%*[^0-9]%d%*[^0-9]", lock_sz) != 1)
+		tst_brk(TFAIL | TERRNO, "Getting locked memory size failed");
 
-	fclose(fstatus);
+	fclose(fp);
 }
 
-static void setup(void)
+static void run(void)
 {
-	tst_require_root();
+	unsigned int sz_after, sz_diff;
 
-	tst_sig(FORK, DEF_HANDLER, cleanup);
+	addr = mmap(NULL, MMAPSIZE, PROT_READ | PROT_WRITE,
+				MAP_PRIVATE | MAP_LOCKED | MAP_ANONYMOUS, -1, 0);
 
-	TEST_PAUSE;
-}
+	if (addr != MAP_FAILED) {
+		tst_res(TPASS, "mmap() with MAP_LOCKED flag passed");
+	} else {
+		tst_res(TFAIL | TERRNO, "mmap() failed");
+		return;
+	}
 
-static void cleanup(void)
-{
+	getvmlck(&sz_after);
+	sz_diff = sz_after - sz_before;
+	TST_EXP_EQ_LU(MMAPSIZE / 1024, sz_diff);
+
+	SAFE_MUNMAP(addr, MMAPSIZE);
 }
+
+static struct tst_test test = {
+	.setup = setup,
+	.test_all = run
+};
-- 
2.43.0


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Re: [LTP] [PATCH v3] syscalls/mmap14: Rewrite test using new LTP API

[Petr Vorel]

Hi Avinesh,

> diff --git a/testcases/kernel/syscalls/mmap/mmap14.c b/testcases/kernel/syscalls/mmap/mmap14.c
...
> -/*
> - * Test Description:
> - *  Verify MAP_LOCKED works fine.
> - *  "Lock the pages of the mapped region into memory in the manner of mlock(2)."
> +/*\
> + * [Description]
>   *
> - * Expected Result:
> - *  mmap() should succeed returning the address of the mapped region,
> - *  and this region should be locked into memory.
> + * Verify that, mmap() call with MAP_LOCKED flag successfully locks
> + * the mapped pages into memory.
>   */
> -#include <stdio.h>
> -#include <sys/mman.h>

> -#include "test.h"
> +#include <stdio.h>
> +#include "tst_test.h"

> -#define TEMPFILE        "mmapfile"
> -#define MMAPSIZE        (1UL<<20)
> +#define MMAPSIZE        (1UL<<22)
I wonder why it was needed to increase the map size.
Anyway, even with 1UL<<20 it's too high for old SLES 15-SP1.

ulimit -l prints 64 (kB => 65536) ...

> +static void setup(void)
>  {
> +	SAFE_GETRLIMIT(RLIMIT_MEMLOCK, &rlim);
...
> +	if (((sz_before * 1024) + MMAPSIZE) > rlim.rlim_cur)
> +		tst_brk(TCONF, "Trying to exceed RLIMIT_MEMLOCK limit");
... therefore it TCONF here in the setup function.

But disabling this check it runs OK. I would expect we would get EAGAIN
(according to man "The file has been locked, or too much memory has been
locked") or MAP_FAILED or ENOMEM (but man says: "This implementation will try to
populate (prefault) the whole range but the mmap() call doesn't fail with ENOMEM
if this fails.")

Just experimenting, to increase to 1UL<<40 I get ENOMEM, doing really too huge
1UL<<200 I get EINVAL.

Therefore I would say the check in this way is wrong.
Or, could we just run SAFE_SETRLIMIT(RLIMIT_MEMLOCK, ...) in case of low limit
and increase it in cleanup?

>  }

>  void getvmlck(unsigned int *lock_sz)
>  {
> -	int ret;
>  	char line[LINELEN];
> -	FILE *fstatus = NULL;
> +	FILE *fp = NULL;

> -	fstatus = fopen("/proc/self/status", "r");
> -	if (fstatus == NULL)
> -		tst_brkm(TFAIL | TERRNO, NULL, "Open dev status failed");
> +	fp = fopen("/proc/self/status", "r");
SAFE_FOPEN() (requires #include "tst_safe_stdio.h") and 2 lines below aren't
needed.

> +	if (fp == NULL)
> +		tst_brk(TFAIL | TERRNO, "could not open status file");

> -	while (fgets(line, LINELEN, fstatus) != NULL)
> +	while (fgets(line, LINELEN, fp) != NULL) {
>  		if (strstr(line, "VmLck") != NULL)
>  			break;
> +	}

> -	ret = sscanf(line, "%*[^0-9]%d%*[^0-9]", lock_sz);
> -	if (ret != 1)
> -		tst_brkm(TFAIL | TERRNO, NULL, "Get lock size failed");
> +	if (sscanf(line, "%*[^0-9]%d%*[^0-9]", lock_sz) != 1)
> +		tst_brk(TFAIL | TERRNO, "Getting locked memory size failed");

I would say this should be tst_brk(TFAIL | TERRNO) (it's not directly related to
the testing, more to the preparation). Also I hope Andrea Manzini will add his
first easyhack for SAFE_SSCANF() and he will use it :).

The rest LGTM.

Kind regards,
Petr

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